The Yangtze River's last surviving mammal

Little known even to people who live in China’s Yangtze River Basin, a shy mammal with a secret smile has been pulsing through the waters of Asia’s longest river for some 100,000 years.

Wary of humans, the finless porpoise stays hidden below the river’s surface. Locals, unsure of what they looked like, simply called them “river pigs.” Despite being humankind’s closest aquatic relative in the 6,300-kilometer river, and as smart as the gorilla, the porpoises never made it to popular conscience.

But when their more famous cousin, the pink Baiji dolphin, was declared effectively extinct in 2006 in the same waters, the finless porpoise suddenly took the uncomfortable distinction as the Yangtze’s last surviving mammal.

Yangtze Finless Porpoise

Neophocaena asiaeorientalis

Status

Critically Endangered

The Yangtze finless porpoise lives in the Yangtze River, the longest river in Asia. At one point, this porpoise shared the waters with the Baiji dolphin—a species declared functionally extinct in 2006. The Yangtze finless porpoise is known for its mischievous smile, and its intelligence level is on par with a gorilla.

Today, the fate of the finless porpoise foreshadows the health of the whole river system. An indicator species, its well-being means food, transport and livelihoods for some 500 million people.

As China reaches new economic heights, the critically endangered finless porpoise is fighting an uphill battle for survival in increasingly toxic waters that hold a dwindling fish stock. Today, there are just around 1,000 porpoises (fewer than the number of giant pandas in China) navigating theYangtze’s twists and turns. Each year, about another 10% of the population is lost. Conservation biologists estimate a greater than 50% chance of extinction in the next 10 years if protective measures are not taken.

At Dongting Lake, midstream on the Yangtze river, hundreds of colossal dredging vessels and barges spit out sand scraped from the bottom of the river. While harvesting the sand that will become the concrete for metropolises like Shanghai, the machines also grab lobsters, prawns and riverbed vegetation, destroying the porpoise’s habitat and food source. Their noise and propellers pose mortal danger to the delicate mammals, which use sonar to navigate the river’s landscape.

“The finless porpoise can be dragged into the powerful suction force created by the propeller,” says Zhang Xinqiao, manager of species protection for WWF China, citing forensic evidence.

Porpoise calves can get separated from their mothers by the motor noises. Very young calves can drown if left alone; older ones get lost and struggle to hunt with their underdeveloped sonars.

The finless porpoise’s habitat overlaps with other threatened and endangered species from the Yangtze crocodile to the Chinese sturgeon. Protecting the porpoise would in turn protect the whole ecosystem, what WWF calls the “umbrella effect.”

“If the dolphin went extinct, we would have failed to save the river,” says WWF’s China’s Head of Water Practice, Ren Wenwei. “What does that say about the river’s ability to provide for humans?”